Abstract : Experimental studies of air augmented metal combustion have been made using an explosion vessel technique for generating a fuel-rich, particle-laden exhaust. A hydrogen/oxygen/nitrogen propellant system provided the primary combustion source for heating the metal particles in the main experimental effort. The sonic primary exhaust reacted with sonically injected air in an unnozzled secondary combustor at one atmosphere pressure. Photographic and spectroscopic techniques were used to qualitatively determine the ignition and secondary combustion characteristics of aluminum and boron particles. The experimental parameters examined were: (1) particle size, (2) metal loading, (3) primary combustor temperature, (4) secondary air temperature, and (5) air-to-propellant ratio. Within the parameter ranges covered, only metal loading exhibited little influence on ignition. The spectroscopic data indicates that the secondary combustion of aluminum occurs according to a gas phase mechanism. (Author)